Abstract: After analyses the thought that people are the foundation of country at the period of the end of Ming dynasty and the beginning of Qing dynasty, in three aspects and concludes that the thinkers of the period had made this thought of ancient China to a head in the history. But people should also catch sight of that the motive force of the thinkers' thought still came from the tradition, originated from traditional thoughts. At the same time as the thought showed its progressive significance to common people, its defects disclosed, which made clear that the thinkers' understanding hadn't entered the threshold of "modern times" after all.